server/src/routes/files.ts

```typescript
import { Router } from "express";
import multer from "multer";
import path from "path";
import fs from "fs";

export const filesRouter = Router();

const uploadDir = path.resolve("src/storage/uploads");
fs.mkdirSync(uploadDir, { recursive: true });

const storage = multer.diskStorage({
  destination: (_req, _file, cb) => cb(null, uploadDir),
  filename: (_req, file, cb) => cb(null, Date.now() + "_" + file.originalname)
});

const upload = multer({ storage });

filesRouter.post("/upload", upload.array("files", 10), (req, res) => {
  const files = (req.files as Express.Multer.File[]) ?? [];
  res.json({
    ok: true,
    files: files.map(f => ({ name: f.originalname, path: f.filename, size: f.size }))
  });
});
```